Step 1. Create WAM iiiTreeView – Using a Tree View Weblet

WAM075 - Using a Tree View Weblet

Unlevelled List

In an unlevelled list each entry tells the Tree View exactly where it fits in the tree structure by specifying its parent ID. As a minimum, an unlevelled list must contain columns with the following data:

Field

Tree View Property

Description

ID

list_id_field

A unique ID string to identify the entry.

Parent ID

list_parent_id_field

The ID string of the parent entry. An empty string indicates a top level entry.

Caption

list_caption_field

The text to display for the entry.

The Tree View processes the list entries in the supplied order and cannot add an entry to a parent that doesn't exist. It is your responsibility to ensure the list is sorted so that parent items come before their children and items at the same level are in display order.

Additional list fields may be used to control the tree view behaviour and appearance:

Your WAM will build an initial list based on the department table (DEPTAB), so that initially the tree will contain a single level. You will later add routines to handle expanding the tree view at each level.

Note: The supplied code can be copied from the WAM tutorials in the Visual LANSA online guide. Most of the code to support the tree view is provided, but you should ensure that you review it in detail so that you become familiar with the concepts.

1. Create a new WAM:

Name: iiiTreeView

Description: Using a Tree View Weblet

Layout Weblet: iiilay01

Make a note of the Identifier which is assigned to this WAM. You will need to use the Identifier when setting the WAM Name field in the working list which builds the tree view. JavaScript will call the WAM/WebRoutine to display details for the selected level. This requires the WAM Identifier, not the Long Name.

4. Compile the WAM and open the deptview WebRoutine in the Design view.

5. Drop a tree view weblet onto the page. Select the tree view weblet and drag the center right hand "handle" to make the tree view wider to allow room for three levels and descriptions to be displayed.

6. Set up the tree view properties as follows:

Property

Value

Listname

EMPTREE

item_image

icons/normal/16/operator_16.png ***

list_caption_field

LISTCAPT

list_id_field

LISTID

list_onselect_wamname

SELWAM

list_onselect_wrname

SELWRN

list_haschildren_field

HASCHLD

list_parent_id_field

LISTPID

*** select the image using the Ellipsis button. Drill down by selecting the normal and 16 folders.

7. Save your changes and run the WAM in the browser. Your tree view should display description for all departments: